Twist-in lamp socket



NOV. 24, 1970 w, BEDFQRD, JR" ET AL 3,543,225

TWI ST-IN LAMP SOCKET Filed June 27, 1968 US. Cl. 339-127 United States Patent 3,543,225 TWIST-IN LAMP SOCKET William A. Bedford, Jr., Sarasota, Fla., and Don L. De Lano, Mount Clemens, Mich., assignors, by mesne assignments, to Microdot Inc., Greenwich, Conn., a corporation of California Filed June 27, 1968, Ser. No. 740,573 Int. Cl. H01r 13/20 4 Claims ABSTRACT OF THE DISCLOSURE The disclosure relates to a lamp socket which is retained and locked in position in an aperture by an axial and rotatable movement.

BACKGROUND OF THE INVENTION A plurality of arcuate spring fingers have heretofore been employed for holding a socket to the wall of an aperture by means of an axial movement of the socket to within the aperture. Fingers have also heretofore been provided which engage the wall of the aperture and, upon a turning movement of the socket, lock the socket within the aperture.

The present invention provides a socket so formed from spring sheet material as to have both types of fingers, one set of fingers having a major diameter which passes beyond the wall of the aperture for producing a spring holding force and a set of fingers therebetween having a notch which engages one side of the supporting wall upon the rotational movement of the socket. This positively clamps the socket on to the wall and adds to the holding force provided by the spring fingers.

Two or more fingers of each type are alternately disposed on the socket and the aperture in which the socket is clamped has three recesses for receiving the fingers having the notch therein. One notch and finger is of greater width than the other notch or notches and fingers for orienting the socket within the aperture.

Accordingly, the main objects of the invention are: to provide a socket with spring fingers which lock upon the axial inserting of the socket in the aperture and notched fingers which engage the supporting wall when the socket is rotated in the aperture; to make both sets of locking fingers from a sheet of spring steel which is secured to the socket tube by the reversed edge of a flange at the end of the tube, and in general, to provide a socket with locking fingers which are simple in construction, positive in operation and economical of manufacture.

Other objects and features of novelty of the invention will be specifically pointed out or will become apparent when referring, for a better understanding of the invention, to the following description taken in conjunction with the accompanying drawing, wherein:

FIG. 1 is an enlarged plan view of a socket of the present invention mounted in an aperture in a supporting panel;

FIG. 2 is a reduced view of the aperture in the panel in which the socket is supported;

FIG. 3 is a broken sectional view of the structure illustrated in FIG. 1, taken on the line 3-3 thereof, and

FIG. 4 is a broken sectional view of the structure illustrated in FIG. 1, taken on the line 4-4 thereof.

It will be noted from the figures, that a supporting panel 11 has a central annular aperture 11 containing slots 13, 14 and 15, and that the slot 15 is wider than the slots 13 and 14. The socket has a tube 16 having a flange 17 at one end, the outer end 18 of which is reversely bent over "ice a disc 19 of a spring material containing two sets of fingers 21 and 22, herein illustrated as three in number and alternately disposed. The fingers 21 are arcuately shaped on a section of a sphere of greater diameter than the diameter of the aperture 12 to provide spring engagement therewith when inserted with an axial movement within the aperture as clearly illustrated in FIG. 3. The fingers 22 are angle shaped having an inner supporting portion 23 and an outer lip portion 24, the bottom end 25 of which rides upon the outer surface 26 of the panel 11, as clearly illustrated in FIG. 4. A stop projection 27 on the lip portion 24 limits the rotational movement of the socket to accurately orient bayonet slots 28 located in the wall of the tube 16. The slots 28 receive the pins projecting outwardly from the base of the bulb in diametric relation to each other with one locking notch 30 extending further inwardly from the end of the tube 16 so as to properly position the lamp bulb in the socket.

A terminal block 29 has terminals 31 pressed by a spring 32 against the terminals of the lamp bulb. The leads 33 of the terminal pass out of the bottom of the socket and may be sealed by a sleeve as is the common practice in the art. It will'be noted that one finger 35 of the set 22 is wider than the other two fingers and that the slot 15 is wider than the other two slots 13 and 14. Since the finger 35 must be located in the slot 15, assurance is provided that the socket will be properly oriented when mounted in the aperture 12.

It will be noted that the spring disc 19 has downwardly extending flanges 36 in the tube 16 which are employed for stabilizing the base of the bulb when mounted within the socket. It will be seen that such a socket requires a simple aperture for its support and that the wider finger of the socket and the wider slot in the aperture wall will positively orient the socket within the aperture, since stop means limits the rotational movement of the socket. A substantial retaining force is provided by the spring fingers 22 which clamp a ring seal 37 between the surface of the panel 11 and that of the reversely bent end -18 of the flange 17 on the end of the socket tube 16. The entire socket is easily removed from the panel for bulb or other servicing and is easily installed within the aperture thereafter. It is very apparent that any change in the gauge of the material of the panel will be taken up by the spring material of the supporting and lip portions 23 and 24 of the finger 22 and that none of the parts of the socket will be damaged due to a variation in the thickness of the supporting panel.

What is claimed is:

1. In a socket having a tube containing a terminal block and bayonet slots for supporting the base of a bulb, two sets of fingers on the tube for supporting the socket, supporting element having an aperture which has a plurality of notches extending inwardly from the edge thereof, one set of fingers being concaved inwardly, the other set of fingers being alternately disposed between the said first set of fingers and each being of inverted U-shape providing an outer downwardly presenting lip the bottom edge of which engages the supporting element to lock the socket thereon when the second set of fingers are inserted through the notches in the apertures and the socket is rotated thereafter for locking the socket on the element.

2. In a socket as recited in claim 1, wherein each set comprises at least two fingers positioned alternately relative to each other.

3. In a socket as recitedvin claim 1, wherein one notch is of relatively greater width and substantially that of one of the fingers which it receives to properly orient the socket in the element.

4. In a socket as recited in claim 1, wherein the end of at least one of the lips is notched at the end to provide a stop for limiting the rotation of the socket within the aperture.

References Cited UNITED STATES PATENTS 2,457,488 12/1948 Penfold 339-126 X 2,731,613 1/1956 Heller 339-128 2,849,697 8/1958 Farison 339127 4 2,928,065 3/1960 Hennessy et a1 339--128 2,982,939 5/1961 Kirk 339-127 3,362,007 1/1968 Delano 339-127 3,378,812 4/1968 Fitzgerald 339-127 FOREIGN PATENTS 372,140 5/1932 Great Britain.

RICHARD E. MOORE, Primary Examiner 

